The solidification segregation behavior of deposited metal with nickel alloy wires by GTAW was investigated by Optical Microscope (OM), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Electron probe X-ray microanalyser (EPMA), etc. Results indicated that microstructure was composed of γ phase, MC carbides, Laves phases in the deposited metal. The metallurgical structure was columnar crystals with segregation zone of 5~10 μm in width. The segregation coefficients of primary elements were calculated with EPMA results according to Scheil formula, kNb=0.23, kMo=0.68, kNi=1.07, kCr=1.05, kFe=1.23. During solidification, Nb and Mo tended to segregate in the liquid phase, while Fe prefers to distribute into solid phase, Ni and Cr did not show significant distributions differences between liquids and solids. The reaction sequence of deposited metal with experimental nickel alloy wires during solidification was L→L+γ→L+γ+MC→L+γ+MC+Laves→γ+MC+Laves.
GUO Xiao
,
XU Kai
,
HUO Shubin
,
CHEN Peiyin
,
CHEN Bo
. Investigation on the solidification segregation behavior of GTAW nickel alloy deposited metal[J]. Transactions of The China Welding Institution, 2019
, 40(7)
: 105
-108
.
DOI: 10.12073/j.hjxb.2019400190
[1] 吴伟,陈佩寅,张锐.镍基焊接材料高温失塑裂纹的研究现状及研究趋势[J].焊接, 2005(5):5-8 Wu Wei, Chen Peiyin, Zhang Rui. Research status and development and ductility dip cracking of nickel-welding material[J]. Welding&Joining, 2005(5):5-8
[2] 唐正柱,陈佩寅,吴伟. Nb对镍基合金高温失塑裂纹敏感性的影响机理[J].焊接学报, 2008, 29(1):109-112 Tang Zhengzhu, Chen Peiyin, Wu Wei. Effect of niobium on ductility drop cracking susceptibility of nickel-base alloys[J]. Transactions of the China welding institution, 2008, 29(1):109-112
[3] 唐正柱,陈佩寅,吴伟. Nb和Ti对高温失塑裂纹敏感性影响机理研究[J].焊接, 2007(11):37-41 Tang Zhengzhu, Chen Peiyin, Wu Wei. Investigation into the mechanism for the affection of Nb and Ti ductility dip cracking susceptibility[J]. Welding&Joining, 2007(11):37-41
[4] Dupont J N, Notis M R, Marder A R, et al. Solidification of Nb-bearing superalloys:Part I. reaction sequences[J]. Metallurgical&Materials Transactions A, 1998, 29(11):2785-2796.
[5] Dupont J N, Marder A R, Notis M R, et al. Solidification of Nb-bearing superalloys:Part Ⅱ. pseudoternary solidification surfaces[J]. Metallurgical&Materials Transactions A, 1998, 29(11):2797-2806.
[6] 董建新,张麦仓,曾燕屏.含铌高温合金液相中铌偏聚行为[J].工程科学学报, 2005, 27(2):000197-201 Dong Jianxin, Zhang Maicang, Zeng Yanping. Calculation of Nb segregation behavior in liquid phase for Nb-rich superalloys[J]. Chinese Journal of Engineering, 2005, 27(2):000197-201
[7] Dupont J N, Robino C V, Marder A R. Solidification modeling of Nb bearing superalloys[R]. Office of Scientific&Technical Information Technical Reports, 1997.
